Slip clutch for operating cranks under load



Jan. 3, 1967 T. MADLAND 3,295,256

SLIP CLUTCH FOR OPERATING CRANKS UNDER LOAD Filed June 26, 1963 5 heets-Sheet 1 FIG. I

INVENT OR. TH ORVALD MADLAND ATTORNEYS Jan. 3, 1967 T. MADLAND SLIP CLUTCH FOR OPERATING CRANKS UNDER LOAD Filed June 26, 1963 5 Sheets-Sheet 2 mm TA L D V m E l 2 w my I|l 3 A 1 1mm I- V 1 11! i: R ILITI 0 II" N W 5 mm 5 W 2 8 a 2 0 f 3 3 4 2 h l l.l\, 3 G G \I liuu|lwwli II .II \3 F F 9 3 -l r W. N m II 7 fl VII q L m l l l l l i 0 r 4 L Y u 3 M. 3

ATTORNEYS Jan. 3, 1967 T, MADLAND 3,295,256

SLIP CLUTCH FOR OPERATING CRANKS UNDER LOAD Filed June 26, 1963 5 Sheets-Sheet 5 a; 3 0 3' LO w IO m N I) 3 v N o I) LL (9 '0 m g INVENTOR, THORVALD MADLAND ATTORNEYS United States Patent 3,295,256 SLIP CLUTH FOR OPERATING CRANKS UNDER LOAD Thorvald Madland, Arlington Heights, 111., assignor t0 Youngstown Steel Door Company, Cleveland, Ohio,

a corporation of Ohio Filed June 26, 1963, Ser. No. 290,687 7 Claims. (Cl. 49219) This invention relates to a slip clutch for operating cranks under load and, more specifically, to a device for opening railroad car doors.

In its broadest aspect, this invention relates to a device whereby a crank under load may be rotated to an initial position whereupon the load on the crank will cause continued rotation of the crank independently of the initial actuating force.

In its most specific aspect, the invention relates to an operating mechanism for a railroad car door with the pressures exerted by the contents of the car against the door being utilized to continue the opening movement of the door despite cessation of the initial actuating force.

The so-called flush or plug door is a commonly used type of door in the railroad car industry. To expose the door opening, it is necessary to displace the plug door laterally away from the side of the car and then move the door along guide tracks longitudinally the length of the car. To accomplish the lateral displacement of the door, there is provided a plurality of cranks which are mounted on manually operated pipes secured to the door. These cranks are disposed normal to the plane of the door when the door is in a closed position with the cranks interposed between the door and the track thereby assuring that any force exerted on the door by the contents of the car will not displace the door laterally from its closed position. i

To open the door, it is necessary to rotate the cranks to a position approximately parallel to the plane of the door. This rotation of the cranks is accomplished by manually rotating the pipes upon which the cranks are mounted. Since the contents of the car exert a force normal to the door, considerable friction between the cranks and the guide track must be overcome before the cranks may be rotated. However, once the cranks have been rotated to a certain angular position, the frictionv force on the cranks is overcome and the force exerted by the contents of the car then serves to aid in the opening movement of the door. At such time, further manual eiiort exerted on the operating levers of the pipes will be superfluous, and, in fact, will tend to restrain the opening movement of the door.

Inasmuch as the opening force on the door is needed only for a short period of time, it has been found desirable to uncouple the operating lever from the crank-operating pipes at precisely the point where the internal force acting on the door is sufficient to overcome the force of friction and complete the opening movement. This is desirable from two standpoints. First, it allows quicker and easier operation of the door opening process. Secondly, once the internal force on the door overcomes the frictional forces, the operating lever ceases to be under the control of the operator, due to the superior force exerted by the contents of the car, thereby tends to become a source of possible injury to the operator.

It is an object of this invention to provide a slip clutch for operating cranks under load.

It is a further object of this invention to provide an Patented Jan. 3, 1967 overrunning clutch interposed between an operating lever and its associated rotatable member.

It is a still further object of this invention to provide a clutch device in the mechanism for operating railroad car doors.

It is another object of this invention to provide a mechanism that will allow the force exerted by the contents of a railroad car to complete the opening movement of the car door independently of the initial actuating mechanism.

It is still another object of this invention to provide a mechanism for operating the cranks on a railroad car plug door wherein the mechanism includes a reversible overrunning clutch interposed between the cranks and the operating lever.

It is a more specific object of this invention to provide a door operating mechanism including a plurality of rotatable cranks secured to the door with manually operable handles associated with each of the cranks for rotating the same thereby to displace the door laterally in the door opening, and an overrunning clutch interposed between each of the cranks and its associated handleso that, in the event the angular velocity of the cranks exceeds that of the handles, the handles automatically will be disconnected from the associated crank.

To the accomplishment of the foregoing and related ends, said invention then consists of the means hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail one approved means of carrying out the invention, such disclosed means, however, constituting but one of the various ways in which the principles of the invention may be used.

In the drawings:

FIG. 1 is a front elevational view showing the invention as it is incorporated in a railroad car door.

FIG. 2 is a side elevational view taken along line 2-2 of FIG. 1.

FIG. 3 is a View taken along line 3-3 of FIG. 1 showing the clutch device.

FIG. 4 is an elevation view of the slip clutch mechanism shown in FIG. 3.

FIG. 5 is a view taken along line 55 of FIG 1.

FIG. 6A is a schematic view showing the initial opening operation of the car door.

FIG. 6B is a view similar to 6A showing the operating mechanism when the force on the door has overcome the force of friction.

FIG. 6C is a view similar to 6A showing the operating mechanism as the door is being closed.

Referring now to the drawings which illustrate one preferred embodiment of the invention, the numeral 10 designates one side wall of a conventional railroad car. A door opening 11 is formed in the side wall and is adapted to be closed by a laterally movable door 12.

In the closed position, the door 12. is seated in the door opening and is substantially flush with the external surface of the side wall to. To move the door laterally out of the door opening 11 for longitudinal movement along the side wall 10 upon the track 13, there are provided spaced apart parallel vertical pipes 14, 15. Each of the pipes 14, 15 is rotatably secured upon the door 12 by means of brackets 16, 17, 18, 19.

Secured to the upper end of the pipe 14, 15 are cranks 2t 21 respectively. The cranks 24), 21 extend upwardly behind a retainer 22 and are provided with rollers 23 which guide the door in its longitudinal movement and retain the top of the door. in the proper position relative to the car. Secured to the lower end of each of the pipes 14, 15 are cranks 24, 25 respectively. The cranks 24, 25 are journalled in roller hangers 26, 27 mounted upon the track 13 thereby to facilitate sliding movement of the door.

It is believed apparent that upon rotation of the pims 14, 15 the upper cranks 20, 21 and the lower cranks 24, 25 are caused to be rotated. As is apparent from an inspection of FIGS. 1 and 2, all of the cranks 20, 21, 24, 25 are normal to the plane of the door when the door is in the closed position. Thus, upon rotation of the pipes 14, 15, the cranks are pivoted to a position approximating a parallel relationship with the plane of the door thereby causing the door to be displaced laterally outward from the plane of the cars siding. After this has been accomplished, the door may be displaced longitudinally along the track 13 thereby exposing the door opening.

To accomplish the rotation of the pipes 14, 15 there is provided a pair of operating levers 28, 29. The lever 28, being exemplary of both levers, is pivot-ally secured by a pin 30 to a clevis 31 thus allowing the lever 28 to be pivoted in a plane parallel to the plane of the door. The clevis 31 is pivotally secured by a pin 32 to a carrier 33 which is free to rotate about the pipe 14. The clevis 31 includes a semicircular recessed portion 34 which defines spaced apart lugs 35, 36.

A cylindrical member 38 is secured by welding, or other appropriate means, to the pipe 14 for rotation therewith. A spring washer 39 is mounted on the cylinder 38 and serves to retain the carriers 33 in a fixed position along the length of the pipe 14.

The intermediate portion of the cylinder 38 contains a semispherical recess 40 which is exposed adjacent to the recess 34 in the clevis 31. The recess 40 provides stop surf-aces 41, 42 which are adapted to be selectively associated with the projecting lugs 35, 36 on the clevis 31.

The selective association of the lugs 35, 36 with the stop portions on the cylinder 38 is accomplished by virtue of the pivotal mounting of the clevis 31. Thus, the clevis 31 may be rotated about the pivot 32 to a position such as shown in FIG. 3 wherein the lug 35 is interposed in direct opposition to the surface 41 on the cylinder 38. Rotation of the clevis 31 in an opposite direction causes the interposition of the lug 36 into the path of the surface 42 and removes the lug 35 from its association with the surface 41.

The device illustrated in FIGS. 3 and 4 comprises an over-running clutch device with the handle 28 the driving member and the pipe 14 the driven member. By rotating the clevis 31 counterclockwise by the driving handle 28, as shown in FIG. 3, the lug 35 cooperates with the surface 41 on the cylinder 38 so that upon further rotation of clevis 31 by the handle 28 a rotative motion is imparted to the pipe 14. Should the rotation of the pipe 14 exceed the angular rotation of the clevis 31, the surface 41 would separate from the lug 35 and the pipe 14 would overrun relative to the clevis 31. The overrunning of the pipe 14 and the cylinder 38 is accommodated by virtue of the semicircular recess 34 in the clevis 31. The same relationship and function would be present between the lug 36 and the surface 42 should the clevis 31 be rotated in a clockwise direction as shown in FIG. 3.

The operation of the clutch device during the opening movements of the door will now be described. It is assumed that the railroad car is filled with a substance which exerts a force outwardly against the door closure with the outward movement of the door being restrained by virtue of the upper cranks 20, 21 and the rollers 23 acting against the retainer 22 and the lower cranks 24, 25 being interposed between the door and the carrier hangers 26, 27. This outward force against the door gives rise to considerable friction between the rollers 23 and the carrier 22 and the cranks 24, 25 and their respective mountings on the guide tracks 13. It is this frictional force that must be overcome in order to rotate the pipes 14, 15 and thereby laterally displace the door from the door opening. Since the cranks are disposed normal to the door and the internal force also is normal to the door, some external force must be used to overcome the frictional force and rotate the cranks.

To open the car door, the operator would release the two levers 28, 29 from a retainer 43 thus allowing the levers 28, 29 to be pivoted in a plane parallel to the plane of the car door. To overcome the frictional force, each of the levers 28, 29 and the associated clevises are pivoted outwardly away from the door to a position shown schematically in FIG. 6A where, in the case of lever 28, the lug 36 on the clevis 31 in abutting relation with the surface 42 on the cylinder 38. A similar position is assumed by the clevis associated with the lever 29. The operator, by exerting a force on the lever 28 causes rotation of the pipe 14 which in turn rotates the cranks 20, 24 against the frictional force. A similar rotation would be imparted to cranks 21, 25 through lever 29.

As the cranks are rotated through an increasing angle, the force exerted by the contents of the railroad car includes an ever increasing component of force which acts opposite to the frictional force. At a particular angle of the cranks, the force exerted on the door by the internal contents will overcome the force of friction and the door will continue its outward movement independently of any further rotation imparted by the levers 28, 29. This condition is schematically illustrated in FIG. 6B wherein the cylinder 38 and the pipe 14 connected thereto are rotating independently of further movement by the clevis 31. This overrunning condition shown in FIG. 6B will continue until the door has completed its lateral displacement at which time the door may be moved longitudinally along the tracks 13, thereby to expose the door opening 11.

To close the door, an operation the reverse of that used to initiate the opening of the door is utilized. Thus, as shown in FIG. 6C, the clevis 31 is rotated to a position wherein the ing 35 may engage the surface 41 on the cylinder 38. Upon this engagement, the clevis 31 is rotated in the direction of the arrow thereby displacing the door laterally inward to a position where the cranks 20, 21, 24, and 25 are again in a position normal to the plane of the door.

A specific example of the principles of this invention is where the force exerted outwardly by the contents in the railroad car is assumed to be 2000 lbs. In such circumstances, after the cranks have been rotated 10, a frictional force which is the product of the load, 2000 lbs., and the coefiicient of friction, 0.4, or 800 lbs. is resisting further rotation of the cranks. Opposing this frictional force is a force of approximately 353 lbs., which force consists of that component of the 2000 lb. force which is acting parallel to the plane of the door. Obviously, since the force of friction is greater than the opposing component of force, there will be no continued rotation of the crank due solely to the load on the door.

When the cranks have been rotated by manually exerted force to a point where the component of force due to the load on the door exceeds the force of friction, the crank will then continue to rotate independently of any further external input. Such a condition has been found to exist when the cranks have been rotated through an angle of approximately 22. When the angle of 22 has been attained and the load on the door is adequate to com plete the opening operation, the overrunning condition illustrated in FIG. 6B occurs and the levers 28, 29 automatically are disconnected from the associated pipes 14, 15.

For ease of description, the principles of the invention have been set forth in connection with but a single illustrated embodiment. It is not my intention that the illustrated embodiment or the terminology employed in describing it be limiting inasmuch as variations in these may be made without departing from the spirit of the invention, but rather, it is my desire to be restricted only by the scope of the appended claims.

In the claims:

1. In combination:

a plug door adapted to close a door opening in the side of a railroad car;

a plurality of pipes rotatably secured to said door;

crank means secured to each end of each of said pipes;

guide tracks on the railroad car receiving said crank means for longitudinal sliding movement of said door;

a manually operable handle means supported by each of said pipes for rotating each of said pipes and thereby to displace said door laterally toward and away from the door opening; and

clutch means connected to each of said handle means and said pipes whereby said pipes may rotate independently of said handle means;

said clutch means comprising:

a carrier rotatably mounted on each of said pipes but secured against longitudinal movement relative thereto;

a clevis pivotally secured to each of said carriers;

said handle means being secured to said clevis;

said clevis including spaced apart lugs defining a semicircular recess therebetween;

a cylindrical member secured to each of said pipes for rotation therewith;

said cylindrical member including a semicircular recessed portion defining spaced apart abutment surfaces;

said clevis being operatively received in the recessed portion in said cylindrical member with one of said lugs being adapted to cooperate with one of said abutment surfaces in one position of said clevis and the other of said lugs being adapted to cooperate with the other of said abutment surfaces in another position of said clevis.

2. An operating mechanism for controlling the rotation of a pipe comprising:

a rotatable pipe;

a manually operable handle supported on and adapted to rotate said pipe;

clutch means interposed between said pipe and said handle whereby said handle may selectively be operatively connected to said pipe for rotating said pipe;

said clutch means comprising a cylindrical member secured to said pipe for rotation therewith;

a carrier rotatably mounted on said cylindrical member;

a clevis pivotally secured to said carrier;

said handle being secured to said clevis;

said clevis including spaced apart lugs defining a semicircular recess therebetween;

said cylindrical member including a semicircular recessed portion defining spaced apart abutment surfaces;

said lugs of said clevis being adapted to be operatively received in the recessed portion in said cylindrical member, with one of said lugs being adapted to cooperate With one of said abutment surfaces in one position of said clevis;

and the other of said lugs being adapted to cooperate with the other of said abutment surfaces in another position of said clevis.

3. An overrunning clutch comprising:

a rotatable driven member;

a cylinder secured to said driven member;

said cylinder including a semicircular recessed portion defining spaced apart abutment surfaces;

a carrier rotatably mounted on said driven member and concentric with said cylinder;

a clevis having a pair of spaced apart lugs thereon;

means pivotally securing said clevis on said carrier for pivoting movement between a first position wherein one of said lugs on said carrier is disposed in the semicircular recess of said cylinder and a second position wherein the other of said lugs on said clevis is received in the semicircular recess in said cylinder whereby said selective disposition of said lugs in said recess permits engagement of said lugs with said abutment surfaces on said cylinder; and

drive means operatively connected to said carrier whereby rotation of said carrier imparts rotation to said driven member through the abutment of said lugs and said surfaces on said cylinder.

4. A reversible overrunning clutch comprising:

a rotatable driven member;

a cylinder secured to said driven member and including a semicircular recessed portion defining spaced apart abutment surfaces;

a carrier rotatably mounted on said cylinder;

a clevis;

means securing said clevis on said carrier for rotation therewith and pivoting movement relative thereto, said clevis including lug means adapted to be received in the recessed portion of said cylinder adapted to engage said abutment surfaces;

and drive means secured to said clevis adapted to pivot said clevis on said carrier and rotate said clevis and carrier relative to said cylinder.

5. The clutch of claim 4 wherein said lug means com- 6. In a railway car having side and end walls defining an interior and a door opening in at least one side wall thereof:

a door adapted to close the door opening;

means mounting said door on said side wall of the car for transverse movement into and out of the door opening and for sliding movement longitudinally of the car;

said mounting means including a pair of vertically extending rotatable pipes secured to said door;

each of said pipes having a crank at either end thereof with said cranks cooperating With means on the side Wall of said car to displace said door into and out of the door opening in the car upon rotation of said p actuating means supported on and connected to said said actuating means including an abutment surface on each of said pipes;

lug means rotatably supported on said pipes for rotating movement independent of said pipes and abutment surfaces;

said lug means being positioned on said pipes adjacent said abutment surfaces whereby selective rotation of said lug means causes engagement with said abutment surfaces whereby said lug means and said pipes are connected for unitary rotation; and

handle means pivotally secured to said lug means;

said pivotal securement of said handle means permitting pivoting of said handle in one plane independent of said lug means and restraining said lug means for rotation with said lug means in a plane transverse to said one plane.

7. In a railway car having side and end walls defining an interior and a door opening in at least One side wall thereof:

a door adapted to close the door opening;

means mounting said door on said side wall of the car for transverse movement into and out of the door opening and for sliding movement longitudinally of the car;

said mounting means including a pair of vertically extending rotatable pipes secured to said door;

each of said pipes having a crank at either end thereof with said cranks cooperating with means on the side wall of said car to displace said door into and out of the door opening in the car upon rotation of said p p actuating means on said pipes for effecting rotation thereof;

said actuating means including abutment surfaces secured to said pipes;

lug means adapted to engage said abutment surfaces;

means supporting said lug means on said pipes for rotation relative thereto;

said supporting means further including means permitting pivotal movement of said lug means relative to said supporting means; and

manual actuating means connected to said lug means adapted to pivot said lug means into engagement with said abutment surfaces.

References Cited by the Examiner 5 UNITED STATES PATENTS 69,399 10/ 1867 Brown. 550,306 11/1895 Welch 74142 X 910,456 1/ 1909 Brush 19243 X 2,577,181 12/ 1951 Christensen 19217 1 3,006,040 10/1961 Madland 20-23 3,148,553 9/1964 Carr 74-142 HARRISON R. MOSELEY, Primary Examiner.

REINALDO P. MACHADO, Examiner.

A. I. BREIER, Assistant Examiner. 

7. IN A RAILWAY CAR HAVING SIDE AND END WALLS DEFINING AN INTERIOR AND A DOOR OPENING IN AT LEAST ONE SIDE WALL THEREOF: A DOOR ADAPTED TO CLOSE THE DOOR OPENING; MEANS MOUNTING SAID DOOR ON SAID SIDE WALL OF THE CAR FOR TRANSVERSE MOVEMENT INTO AND OUT OF THE DOOR OPENING AND FOR SLIDING MOVEMENT LONGITUDINALLY OF THE CAR; SAID MOUNTING MEANS INCLUDING A PAIR OF VERTICALLY EXTENDING ROTATABLE PIPES SECURED TO SAID DOOR; EACH OF SAID PIPES HAVING A CRANK AT EITHER END THEREOF WITH SAID CRANKS COOPERATING WITH MEANS ON THE SIDE WALL OF SAID CAR TO DISPLACE SAID DOOR INTO AND OUT OF THE DOOR OPENING IN THE CAR UPON ROTATION OF SAID PIPES; 